The proposed project aims to improve the characterization of CDRs, and produce new CDRs, for four essential climate variables in the stratosphere (approximately 10-50 km altitude). Where possible the domain of study will extend into the lower mesosphere (to approximately 65 km altitude). In the stratosphere, space-based measurements are the dominant source of CDRs because of the limited extent of in-situ measurements compared with the troposphere, and the near-global coverage of space-based measurements. As a result of the their pioneering developments in the early phase of the space age, the space-based stratospheric CDRs up to the present are reliant primarily on US (NOAA or NASA) data. The purpose of this study is to work towards the inclusion of ESA and ESA-TPM data in the stratospheric CDRs used by the stratospheric research community. This is in fact a pressing need because a number of key US-based CDRs ended in 2005/2006: namely the SAGE-based ozone record, the SAGE-based aerosol record, the SSU-based temperature record, and the HALOE-based water vapour record. Since the ESA and ESA-TPM vertical profile observation records begin a few years before 2005/2006 and continue to the present, there is a period of overlap which allows for a potential extension in time of the existing CDRs. In achieving these objectives, the study will meet the requirements laid out in the statement of work.